feat: Flatten stack structure - all stacks directly in stacks/

- Removed all subdirectories
- Renamed compose.yml to <stack>-compose.yml
- Updated stack.toml to reference new compose file names
- Structure is now flat for easier Komodo sync

New structure:
stacks/
├── prometheus.toml
├── prometheus-compose.yml
├── grafana.toml
├── grafana-compose.yml
├── gotify.toml
├── gotify-compose.yml
├── vaultwarden.toml
├── vaultwarden-compose.yml
└── node-exporter.toml
└── node-exporter-compose.yml

stacks/node-exporter/README.md

@@ -1,63 +0,0 @@
-# Node Exporter
-
-📈 **System-Metriken für Prometheus**
-
-Node Exporter sammelt Hardware- und Betriebssystem-Metriken.
-
----
-
-## 🚀 Quick Start
-
-1. **In Komodo:** Stack auswählen → Deploy
-2. **Server wählen** (wo Prometheus läuft)
-3. **Warten** bis Container läuft
-4. **In Prometheus** als Target hinzufügen
-
----
-
-## 🔧 Prometheus Integration
-
-In Prometheus Config (`prometheus.yml`):
-
-```yaml
-scrape_configs:
-  - job_name: 'node-exporter'
-    static_configs:
-      - targets: ['localhost:9100']
-```
-
----
-
-## 🔐 Secrets
-
-Keine Secrets erforderlich.
-
----
-
-## 📁 Files
-
-- `compose.yml` - Docker Compose Konfiguration
-
----
-
-## 📊 Metriken
-
-Node Exporter exposed Metriken auf Port 9100:
-- CPU Usage
-- Memory Usage
-- Disk I/O
-- Network I/O
-- System Load
-
----
-
-## 🔄 Updates
-
-Wird automatisch aktuell gehalten durch Komodo.
-
----
-
-## 📞 Support
-
-- **GitHub:** https://github.com/prometheus/node_exporter
-- **Docs:** https://prometheus.io/docs/guides/node-exporter/